kernel_xiaomi_mt6877

Evolution-X-Devices/kernel_xiaomi_mt6877

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Ahmed Salem 809ebb3731 ACPICA: Avoid sequence overread in call to strncmp()

[ Upstream commit 64b9dfd0776e9c38d733094859a09f13282ce6f8 ]

ACPICA commit 8b83a8d88dfec59ea147fad35fc6deea8859c58c

ap_get_table_length() checks if tables are valid by
calling ap_is_valid_header(). The latter then calls
ACPI_VALIDATE_RSDP_SIG(Table->Signature).

ap_is_valid_header() accepts struct acpi_table_header as an argument, so
the signature size is always fixed to 4 bytes.

The problem is when the string comparison is between ACPI-defined table
signature and ACPI_SIG_RSDP. Common ACPI table header specifies the
Signature field to be 4 bytes long[1], with the exception of the RSDP
structure whose signature is 8 bytes long "RSD PTR " (including the
trailing blank character)[2]. Calling strncmp(sig, rsdp_sig, 8) would
then result in a sequence overread[3] as sig would be smaller (4 bytes)
than the specified bound (8 bytes).

As a workaround, pass the bound conditionally based on the size of the
signature being passed.

Link: https://uefi.org/specs/ACPI/6.5_A/05_ACPI_Software_Programming_Model.html#system-description-table-header [1]
Link: https://uefi.org/specs/ACPI/6.5_A/05_ACPI_Software_Programming_Model.html#root-system-description-pointer-rsdp-structure [2]
Link: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstringop-overread [3]
Link: https://github.com/acpica/acpica/commit/8b83a8d8
Signed-off-by: Ahmed Salem <x0rw3ll@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2248233.Mh6RI2rZIc@rjwysocki.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[uli: backport to 4.19]
Signed-off-by: Ulrich Hecht <uli@kernel.org>

2025-07-17 10:08:03 +02:00

platform

ACPICA: provide abstraction for raw_spinlock_t

2018-05-10 17:18:45 +02:00

acbuffer.h

ACPICA: adding SPDX headers

2018-03-18 19:08:05 +01:00

acconfig.h

ACPICA: Reference Counts: increase max to 0x4000 for large servers

2018-08-14 23:49:13 +02:00

acexcep.h

ACPICA: Fix exception code class checks